SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '214849f1e32ee5bf779843121ce818812a4183a2e8405504765285cba6543a64' 
  AND token = 'Wa2NN9CFlT8XQueeuSiyILeFGxtWg++N1uygXSosqKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}